Controls Cases Significance
Age (Years)   40.1±9.3 40.4±8.3 P=0.89
Sex Male 16 13 X2=0.355; df 1; p=0.551
  Female 34 37
Diagnosis Rheumatoid arthritis 30 29  
  Systemic Lupus Erythematosis 13 13  
  Sjogrens Syndrome 4 6 NS
  Systemic Sclerosis - 1  
  UCTD/ MCTD 3 1  
Duration of treatment in yearsMedian (IQR) Chloroquine - 3.0 (2.00-5.00)  
  Hydroxy-chloroquine - 6.0 (5.00-7.00)  
Dosage (mg.kg-1.d-1) Chloroquine - 3.7±0.7  
  Hydroxy-chloroquine - 5.6±1.1  
Table 1: Demographic characteristics of the patients.